1. Field of the Invention
The present invention generally relates to function extending apparatuses, electronic apparatuses and electronic systems, and more particularly to a function extending apparatus, an electronic apparatus and an electronic system in which functions of the electronic apparatus are enhanced by attaching the function extending apparatus thereto.
Recently, as computers are being developed quickly and becoming widespread, it is more preferable to produce minimized and lightweight portable computers and to realize an increased variety of functions. In other words, in general, in a case of using a part of a computer system as a portable machine, just the most essential functions and minimized lightweight portability are required. On the other hand, in a case of using the same computer as a desktop, it is required that the computer system can realize a maximum variety of functions by a function extending apparatus.
To realize the above-mentioned computer system, a portable personal computer (PC) which has just the most essential needed functions, such as a notebook computer, and a function extending apparatus extending the PC's functions by attaching to the portable PC are provided.
The extended station requires a large power consumption when the extended station is attached to the portable PC in order to extend functions. In this case, internal batteries mounted in the portable PC are not enough to operate the extended station and enhance functions. Thus, when the extended station is needed, external power is required.
2. Description of the Related Art
FIG.1 shows a diagram illustrating an example of a construction of a conventional electronic system.
Conventionally, an electronic system 1 such as an information processor system includes a notebook PC 10 having essential functions and an extended station 20 that is used with the notebook PC 10 to enhance its functions.
The extended station 20 is mounted to a bottom surface of the notebook PC 10 by connecting a connector 21 with a connector 11 of the notebook PC 10. The extended station 20 includes a floppy disk drive 22 to record or read data stored in a floppy disk 30 and a CD-ROM drive 23 to read data from a CD-ROM 40. The notebook PC 10 does not include any of a floppy disk drive, a CD-ROM drive and a stereo speaker 24, which require much power consumption. The notebook PC 10 however extends its functions to operate the floppy disk drive 22, the CD-ROM drive 23 and a stereo speaker 24 by attaching to the extended station 20.
In this case, power for both of the notebook PC 10 and the extended station 20 is supplied by using an AC adapter 50 or an internal battery pack 12 mounted in the notebook PC 10.
In the conventional electronic system 1, when the extended station 20 is connected to the notebook PC 10, power is supplied and then the functions of the notebook PC 10 are enhanced. In this case, when the notebook PC 10 supplies power only by the internal battery pack 12, the extended station 20 consumes power quickly. Thus, a total operating time is shortened. The internal battery pack 12 can not practically supply power for a whole computer system. Thus, it is required to use the AC adapter 50 as a main power supplier, which limits usage of the electronic system.
In addition, the extended station 20 itself without the notebook PC 10 does not have any effective function.